function makeDate(timestamp: number): Date;
function makeDate(m: number, d: number, y: number): Date;
function makeDate(mOriTimestamp: number, d?: number, y?: number): Date {
  if (d !== undefined && y !== undefined) {
    return new Date(y, mOriTimestamp , d)
  } else {
    return new Date(mOriTimestamp)
  }
}

const d1 = makeDate(123456)
const d2 = makeDate(1, 2, 3)
// const d3 = makeDate(5, 6)  // 依据重载函数参数个数